This invention relates to an improved injection site.
Injection sites are commonly used in hospitals where a parenteral fluid is being fed to a patient intravenously and it is also desired to combine another medicament with the parenteral fluid. In such circumstances, the parenteral fluid is fed via flexible conduit to one inlet of a connecting device, commonly called an injection site. Flexible conduit extends from the outlet of the injection site to an appropriate device for administering the liquid to the patient. The injection site typically carries a second inlet, having a pierceable diaphragm connected thereto. The supplementary medicament may be injected into the second inlet by a hypodermic syringe and it becomes combined with the parenteral liquid for administration to the patient.
Injection sites are commonly used with administration sets such as illustrated in British Pat. No. 1,182,016 entitled "Parenteral Administration of Liquids". Thus a container of parenteral liquid is fed via flexible tubing (through a tubing clamp) to a burette having a main chamber and a downstream drip chamber, from the drip chamber and via flexible tubing (through another tubing clamp) to an injection site, through the injection site and via flexible tubing to a hypodermic needle for intravenous connection to the patient. A sequence of events is required to be performed by an operator for priming the drip chamber in this prior art administration set. Thus the tubing clamp between the drip chamber and the injection site is opened, the drip chamber is squeezed, the tubing clamp is closed while the drip chamber is still being squeezed, and the drip chamber is released after the tubing clamp is closed.
I have discovered a novel injection site which, when connected to the drip chamber outlet, obviates the need for a tubing clamp between the drip chamber and the injection site and obviates the need for the above-mentioned sequence of steps to be performed by an operator for priming the drip chamber. When my novel injection site is connected to the outlet of the drip chamber, in order to prime the drip chamber the drip chamber is merely squeezed and released, and a check valve which forms a part of the injection site automatically restricts back flow and allows the drip chamber to be properly primed.
In U.S. Pat. No. 3,886,937, issued June 3, 1975, a tubular "Y" administration set is disclosed for sequentially delivering a plurality of medical liquids to a patient over prolonged periods of time. A low pressure responsive valve is located in a first arm of the "Y" set, having a structure that opens and closes the first arm in response to changes in relative surface level heights of two gravity feed liquids supplied to the administration set's first and second arms. The patent does not disclose the priming of a drip chamber by merely squeezing and releasing the drip chamber. Additionally, the low pressure responsive valve which is illustrated in duckbill form in one embodiment of the patent, grasps the outside of a collar which may result in separation of the duckbill valve from the housing.
Injection sites having a shape which permits laminar flow of the fluid are disclosed in U.S. Pat. Nos. 4,000,740 and 4,048,995, issued Jan. 4, 1977 and Sept. 20, 1977, respectively, and entitled "Injection Site". The instant invention is an improvement with respect to the injection sites disclosed in these patents.
It is an object of the present invention to provide an injection site having a check valve housing rigidly attached to the first inlet thereof.
Another object of the present invention is to provide an injection site which is simple in construction and easy to manufacture.
A further object of the present invention is to provide an injection site which, when connected to the outlet of a burette drip chamber, obviates the need for a tubing clamp to be interposed between the drip chamber outlet and the injection site.
A still further object of the present invention is to provide an injection site having a check valve housing rigidly attached to the first inlet, with the check valve housing being constructed to hold securely a duckbill valve member therein.
A further object of the present invention is to provide an injection site to which flexible tubing of different diameters may be connected.
Other objects and advantages of the invention will become apparent as the description proceeds.